feat: generate RPM packages for CentOS 7, Rocky Linux 8/9/10

- Update Dockerfile.package to build RPMs for multiple distributions
  using a unified fpm-based approach
- Add RPM maintainer scripts (postinst, prerm, postrm) for proper
  installation and service management
- Update ja4sentinel.spec for CentOS 7+ compatibility
- Add packaging/systemd/config.yml as default configuration
- Update test-rpm.sh to test installation on all 4 target distributions
- Fix CentOS 7 repository configuration (EOL - vault.centos.org)

Generated RPMs:
- el7: CentOS 7 (libpcap >= 1.4.0)
- el8: Rocky Linux 8 (libpcap >= 1.9.0)
- el9: Rocky Linux 9 (libpcap >= 1.9.0)
- el10: AlmaLinux 10 / Rocky Linux 10 (libpcap >= 1.9.0)

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

packaging/rpm/postinst

@@ -0,0 +1,45 @@
+#!/bin/bash
+#
+# postinst - Script d'installation post-RPM pour ja4sentinel
+# Compatible CentOS 7, Rocky Linux 8/9/10
+#
+
+set -e
+
+echo "==> ja4sentinel: Running post-installation script..."
+
+# Set proper ownership
+chown -R ja4sentinel:ja4sentinel /var/lib/ja4sentinel 2>/dev/null || true
+chown -R ja4sentinel:ja4sentinel /var/run/ja4sentinel 2>/dev/null || true
+chown -R ja4sentinel:ja4sentinel /var/log/ja4sentinel 2>/dev/null || true
+chown -R ja4sentinel:ja4sentinel /etc/ja4sentinel 2>/dev/null || true
+
+# Set proper permissions
+chmod 750 /var/lib/ja4sentinel 2>/dev/null || true
+chmod 750 /var/log/ja4sentinel 2>/dev/null || true
+chmod 750 /etc/ja4sentinel 2>/dev/null || true
+
+# Install config if not exists
+if [ ! -f /etc/ja4sentinel/config.yml ]; then
+    echo "==> ja4sentinel: Installing default configuration..."
+    cp /usr/share/ja4sentinel/config.yml /etc/ja4sentinel/config.yml
+    chown ja4sentinel:ja4sentinel /etc/ja4sentinel/config.yml 2>/dev/null || true
+    chmod 640 /etc/ja4sentinel/config.yml
+fi
+
+# Reload systemd and enable service (only if systemd is running)
+if [ -x /bin/systemctl ] && [ -d /run/systemd/system ]; then
+    echo "==> ja4sentinel: Reloading systemd daemon..."
+    /bin/systemctl daemon-reload
+    
+    echo "==> ja4sentinel: Enabling ja4sentinel.service..."
+    /bin/systemctl enable ja4sentinel.service 2>/dev/null || :
+    
+    echo "==> ja4sentinel: Starting ja4sentinel.service..."
+    /bin/systemctl start ja4sentinel.service 2>/dev/null || :
+else
+    echo "==> ja4sentinel: systemd not detected (container environment), skipping service management..."
+fi
+
+echo "==> ja4sentinel: Post-installation complete."
+exit 0